Positive Response to Cardiac Resynchronization Therapy - The Role of NT-proBNP

Positive Response to Cardiac Resynchronization Therapy - The Role of NT-proBNP

Background: Cardiac resynchronization therapy (CRT) is effective, but only 60-70% of patients benefit from the therapy. Despite numerous implantations, identification of predictive factors for response is still a challenge. We sought to assess the correlation of echocardiographic and clinical response to baseline demographics in relation to change in NT-proBNP levels at 6 months.

Methods: 211 patients on optimal medical therapy were included retrospectively (72 ± 10 yrs., 66% LBBB, 48% DCMP, 80% male) and investigated at baseline and 6 months later. Improvement of ≥ 1 NYHA class was used as a marker for clinical response, and >15% reduction of left ventricular end-systolic volume was used to define reverse remodeling. NT-proBNP levels were measured at baseline and at 6 months and were compared to echocardiographic and clinical response status.

Results: Four groups were identified: 1) non-responder, 2) echo responder, 3) clinical responder, and 4) double responder (echo and clinical). Responders were younger (70 vs. 74 years, p=0.04), had better NYHA class (2.1 vs. 2.5, p=0.01) and had lower NTproBNP compared to non-responders at baseline. NT-proBNP slightly increased or remained unchanged in non-responders, whereas reduction in NT-proBNP was of similar magnitude for clinical or echo responders, and was most pronounced for double responders. A reduction of NT-proBNP ≥25% separated nonresponders from responders (p=0.01). No significant differences in NT-proBNP levels and no significant changes in NT-proBNP were found across the responder subgroups.

Conclusion: Six-month reduction in NT-proBNP is most pronounced for “double responders, ” but was comparable in patients with either clinical or echo response. Lack of NT-proBNP reduction can help identify the non-responders for further intervention.